Abstract
Purpose:
To validate a multi-dimensional, quantitative eye pain questionnaire, the Ocular Pain Assessment Survey (OPAS), and determine the impact of corneal pain on quality of life (QoL).
Methods:
An IRB-approved, single-center, prospective study was conducted over a 6-month period. 103 patients with corneal eye pain were enrolled in the study and assessed using the new multi-dimensional OPAS, of which 21 patients had a post-treatment follow up visit. The FACES Visual Analog Scale served as the gold standard scale for measuring eye pain intensity. Validation and reliability tests were performed both at baseline and follow-up visits.
Results:
The OPAS had strong validity at both visits (initial: rs= 0.71, follow-up: rs= 0.97, P<0.01). The 24-hour eye pain intensity test scale showed equivalence to the gold standard scale for both visits. Factor analysis generated 6 reliable, multi-dimensional sub-scales (Cronbach’s alpha > 0.83), namely, eye pain intensity at 24 h and 2 weeks, non-eye pain intensity, quality of life, aggravating factors and associated symptoms. These correlated positively with the gold standard (r= 0.81, 0.64, P< 0.001). At baseline, QoL correlated strongly to the test pain scale (r=0.77, P<0.001). At follow-up, improvement in scores was seen in the 24-hour eye pain intensity (initial= 3.4±2.5, follow-up= 2.8±2.8) and QoL (initial= 5.1±3.5, follow-up= 4.5±3.7) scales, which correlated to the gold standard (r= 0.68, r= 0.52, P<0.05). With a 29.9% decrease in the average 24-hour eye pain intensity, improvement was also seen in the QoL sub-scale (15.8%) and its constituent scales, specifically, time spent thinking about eye pain (29.8%), mood (26.8%) and the ability to drive and watch TV (21.7%). The associated symptoms sub-scale also demonstrated improvement with reduction in corneal pain, specifically, eye redness (25.8%) and associated non-eye pain (46.7%). The QoL score at follow-up maintained high correlation with both the gold standard and corneal pain related sub-scale scores (r≥ 0.67, P< 0.01).
Conclusions:
The OPAS is a valid and reliable tool in the quantification and monitoring of corneal pain and its impact on the quality of life. The OPAS demonstrated significant decline in QoL and associated symptoms with improvement in corneal pain at follow-up. The OPAS may be utilized in detecting treatment-based changes for corneal pain and QoL.
Keywords: 468 clinical research methodology •
479 cornea: clinical science •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials